What Spine? (Bareshaft Pics Inside)

[TX_Diver]

45lb Uukha Gobi Longs on a 21" Satori riser. I'll probably drop to a 19" at some point just as an FYI. Drawn to about 30" so probably pulling ~50 lbs or so. Shooting off a 25oz springy rest but I have the other springs too and can drop up or down a spring size.

Shooting a 34" 350 spine vintage with 50gr hot glued in the front. No wrap on the back although I'll add one and 3x 5" feathers later.

Pretty much everything from 85gr to 150 gr gave me a solid left tear. 3 rivers spine calculator puts me closest w/ 100 gr points...

I can cut 1" off no problem, and maybe even 2, but my 32" shafts don't give me a great sight picture as they are just in front of the riser. For reference a 340 gr Easton 6.5 tuned w/ a 12 gr insert and a 200gr point. I was really hoping to shoot a brass insert though if possible.

Vintages top out at 350 spine as an FYI.

Full length w/ 100gr point is 502 gr total arrow weight (once I add fletchings etc.).

Apparently I never shot the 100s but here is 85, 125, 150, & 200 gr points. Open to suggestions on what to try. I can obviously adjust centershot with the springy rest too. The 85 with contact denotes me hitting my ceiling joist w/ the top limb so disregard those.

Shots are about 6-7' from paper btw.

 

[Jagger0502]

Paper might not get you the right info. On a longbow you are better to bar shaft shoot at 15-20 yards vs fletched. See where they hit and start working from there. The problem with paper tuning is the arrow off of a recurve or longbow moves and bends a lot more than a center shot compound. Plus if you are using a springy rest it is going to have some more correction depending on where you have that rest set.


Try a few shots bare shaft and fletched.

 

[TX_Diver]

Paper might not get you the right info. On a longbow you are better to bar shaft shoot at 15-20 yards vs fletched. See where they hit and start working from there. The problem with paper tuning is the arrow off of a recurve or longbow moves and bends a lot more than a center shot compound. Plus if you are using a springy rest it is going to have some more correction depending on where you have that rest set.


Try a few shots bare shaft and fletched.


View attachment 465169

I just have one arrow of each spine so I can't really shoot groups to compare.

I did get pretty close with my other bow (19" lark w/ 30lb trad tech black max 2.0s) off the shelf. 500 spine w/ 50gr insert and 100gr point. I'll probably cut an inch and see if I can get the 125s to fly though.

 

[Rob5589]

I would try moving the springy away from the riser and see what you get. Personally I skip paper and go straight to bareshaft and slow motion video. Ultimately you may need to cut or go to a .300.

 

[Wrench]

I'm shooting #55 irbis on a 19" lark with 340's at 31.5". 190 head, 50 gr insert, 24gr footer.....about the same draw.

Are you shooting vertical bow?

Hows your form?

 

[TX_Diver]

I'm shooting #55 irbis on a 19" lark with 340's at 31.5". 190 head, 50 gr insert, 24gr footer.....about the same draw.

Are you shooting vertical bow?

Hows your form?

Form is okay probably but I don't claim to be perfect. I've done a few lessons with Tom Clum but I'm still pretty new to this. But the tears match what I'd expect as I increase/decrease point weight though, and I can get a fairly consistent "bullet hole" with the lark and with the other arrows, so I think my form is probably "okay enough" to get me close which is all I'm ultimately trying to do here.

I am shooting with the bow vertical.

 

[bobinmi]

I think you are overspined with the 340s. Id drop to a 400. For reference, I'm pulling 52lbs at 29 inches with uukha selengas, I've got a springy with the 25lb spring and I'm shooting 400 spine axis 5mm with 230grns of total weight up front.

 

[TX_Diver]

I think you are overspined with the 340s. Id drop to a 400. For reference, I'm pulling 52lbs at 29 inches with uukha selengas, I've got a springy with the 25lb spring and I'm shooting 400 spine axis 5mm with 230grns of total weight up front.

10-4. I will give it a try with the 400s out of curiousity too and see what happens.

This is the tear I get with the full length (think 32") Easton 6.5s with a 21gr insert and 200gr head. I'll also drop a 50gr insert in one and try it with 150s.

 

[will16_]

What does your center shot look like? Is the arrow straight down the riser with the string or the point slightly left? That is where my best results usually come from.

 

[TX_Diver]

What does your center shot look like? Is the arrow straight down the riser with the string or the point slightly left? That is where my best results usually come from.

It is pretty much straight down the riser, maybe even pointing just barely right, but pretty much dead on.

Here's some more. 400 spine vintage definitely appears weak (still 34" long).

I played with the 32" Easton 6.5s with a 50gr insert on most of the right hand side tears. Nomenclature was Arrow / Spine / Insert Weight / Point weight. Some were fletched so I noted Bare for the bareshafts.

From this it seems that a 32" 340 Spine Easton 6.5 with either a 21gr insert and a 200gr head, or a 50gr insert and 150gr head would be my best bet. Just need to figure out if I can get similar results from a 33" or 32.5" 350 Vintage.

 

[Rob5589]

Generally for a right handed shooter the arrow should point slightly left of the string. Opposite if you're left of course. My ilf runs about half an arrow width left of the string.

 

[will16_]

If you want to shoot a 34" shaft, try pushing your center shot out to where the right side of the point/insert is on the left side of the string and see what happens there. Otherwise, start trimming 1/4" at a time. You may also put some electrical tape on the back of the arrow and see if that helps any.

 

[TX_Diver]

Literally just got done shooting and moved center shot. Didn’t make much difference so I’ll cut a 1/2” or so and try again. I’ll add a wrap on the back too. I’m not dead set on 34” but would like to be around 32.5-33” I think (based on what my 32” shafts look like). Thanks!! Will post pics from the computer tomorrow

 

[TX_Diver]

The other thing I can try to (largely just for my own sake of logging data points) is to go up or down a spring weight.

 

[shoeshineman]

350 spine seems too stiff at 50#. Id try your same paper test but with a 400 and 500 spine.


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[TX_Diver]

350 spine seems too stiff at 50#. Id try your same paper test but with a 400 and 500 spine.


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Post 10 has some pics of the 400s with 50gr insert and 150gr points. Strong left tear still. I can try a 500 just for fun but it seems like the 350s probably just need to be cut a bit?

 

[Rob5589]

The other thing I can try to (largely just for my own sake of logging data points) is to go up or down a spring weight.

I did the same thing when scratching my head during tuning. Randy Cooling suggested a #25 for mine but a #20 is what it tuned with. Something to explore absolutely.